Method for vapor treating textile material

ABSTRACT

Method of vapor treating textiles by first supplying vapor so that pressure on one side of material is higher than on the other, then equalizing the pressure, and repeating this process cyclically. Invention includes apparatus for carrying out this process comprising two-compartment chamber with pressure responsive means in one compartment controlling supply of vapor to other compartment.

United States Patent Champel et al. 1 Oct. 2, 1973 [54] METHOD FOR VAPOR TREATING TEXTILE 2,257,519 9/1941 Weiswasser et al 8/1493 X MATERIAL 3,323,l53 6/1967 Fleissner 8/l49.3 3,49l,386 l/l970 Candor et alu... 68/20 X [75] Inventors: Gerard Champel; Franc i O y, 3,592,585 7 1971 Candor et al. 68/20 x both of Montelimar, France FOREIGN PATENTS OR APPLICATIONS [73] Ass'gneei 5mm f 922,289 3/1963 Great Britain 68 189 Joseph Lagarde, Montellmar, France Filed: 1972 Primary Examiner-William I. Price [21] AppL NOJ 217 847 Assistant ExaminerArthur 0. Henderson Attorney-Joseph F. Brisebois et al.

[30] Foreign Application Prlorlty Data ABSTRACT Jan. 18,1971 France 7101460 Method of vapor treating textiles by first supplying 52 us. 01 8/1492, 8/1493, 68/5 c vapor so that Pressure on one d of material is higher 511 1111. C1. D061: 1/04 than on the other, equalizing the Pressure. and [58] Field of Search 8/1492, 149.3; peatihgthis processcychcally- Invention 99 68/5 C 6 20 5| 1552 297 ratus for carrying out this process comprising twocompartment chamber with pressure responsive means [56] Reerences Cited in one compartment controlling supply of vapor to UNITED STATES PATENTS mpmmem 415,191 11/1889 Drown 68/5 C 4 Claims, 2 Drawing Figures L 7 Ila 736 g 25 4/ z 15 ,4 c I 1/ 5 Tip; I 1261 METHOD FOR VAPOR TREATING TEXTHLE MATEREAL This invention relates to a process of vapor treating a textile material, to apparatus for carrying out this process, and to textile materials treated in accordance with this process.

In the textile industry it is conventional to treat threads or textile fibers with vapor in order to impart thereto certain properties, for example to fix them after they have been subjected to a physical treatment, or shrink them. These processes consist in placing the threads or fibers in an atmosphere containing vapor for a predetermined period.

Usually, in these processes, a vacuum is first created and the vapor is then introduced into the autoclave around the fibers to be treated. The establishment of the vacuum permits the vapor to penetrate more rapidly and deeply into the material to be treated, within which the vacuum is first established. It follows that the rapidity of penetration of the vapor into the textile material depends not only upon the characteristics of the material and its shape, but also on the pressure of the vapor. At each moment of treatment, the difference between the pressure around the textile and that inside the same textile decreases as time passes, which slows down the penetration and requires the treatment to be carried out for a considerable length of time in order to render it homogeneous.

By way of example, if a mass of threads or fibers is, after being subjected to vacuum, surrounded by a vapor at 130, which corresponds to an absolute pressure of 2.76 kglcm there is at first a pressure difference of 2.76 kg/cm between the center of the material and the vaporous atmosphere which surrounds it. This difference is no more than 1.72 ltg/cm when the center of the material reaches 100 and 0.73 ltg/cm when it reaches 120 and finally 0.16 kg/cm when it reaches 128. The present invention is intended to provide a process for vapor treating textile materials which will eliminate these disadvantages and thus insure rapid passage of vapor through the textile material, while effectively controlling the temperature inside that mate rial.

it is an object of the invention to provide a process for vapor treating a textile material characterized by the fact that the vapor is passed momentarily through the textile material while establishing apressure difference between the side of the material to which said vapor is supplied and the side from which it leaves said material. The introduction of vapor is then temporarily discontinued while substantially equalizing the pressure on the input side and the output side, and this succession of pressure differences and equalization of these pressures is repeated several times.

The invention thus makes it possible to insure an adjustable pressure difference between the outside and the center of the textile material, which difference in pressure is practically independent of the temperature inside the textile material, which may be kept at a selected value as a consequence of the equalization in pressure.

In accordance with one method of carrying out the invention, the successive alternations between pressure difference and equality in pressure may take place partly while the material is being treated by the passage of vapor therethrough in one direction and partly while vapor is passing therethrough in the opposite direction.

The total duration of alternations between differences and equalizations in pressure while the vapor is passing through the material in one direction may be different from or equal to the duration of the corresponding alternations during passage in the other direction.

in accordance with the invention, it is possible to establish a vacuum inside the textile material being treated before each passage of vapor therethrough, but the invention makes it possible to insure an extremely rapid and homogeneous treatment even in the absence of a preliminary high or partial vacuum.

in one particular method of carrying out the invention the textile material to be treated is located in a container having two open ends, one of which constitutes the vapor entrance and the other the vapor outlet, these two ends being reversed in the course of treatment. However, in another method of carrying out the invention, almost the entire outer surface of the material is left free and a duct is introduced into the center of the material so that the free surface of the material serves alternately as vapor inlet and vapor outlet whereas the internal duct serves alternately as vapor outlet and vapor inlet.

It is a further object of the invention to provide a device for carrying out this process characterized by the fact that it comprises a chamber within which the textile material to be treated is so positioned as to prevent any direct communication between the front or upper part of the chamber and its back or lower part, at least one of the upper and lower or front and back parts being supplied through a vapor supply duct. The opposite part is provided with a vapor outlet duct. These ducts are provided with a valve permitting a higher pressure to be created in a first part of the chamber in a first step so as to force the vapor through the material whereas in a second step this circulation is stopped to permit the two parts of the chamber to reach the same pressure, after which the same alternation is repeated.

in an advantageous variation one of the two parts of the chamber is bounded by the textile material to be treated and may be bounded by the greater part of the surface of the textile material, the other part being bounded by a perforated tubular duct penetrating into the mass of textile material. it is also possible, even though less advantageous from the point of view of technical simplicity, to position the material at the bottom of a chamber with the perforated duct penetrating into the material from the bottom, in which case one of the two parts defined by the material, to wit, the part defined by the perforated tube, is not part of the chamber proper. in a preferred embodiment of the apparatus, the valves are controlled by means of a pressure responsive device which is positioned in the part of the chamber corresponding to the vapor outlet and controls the valve for admitting vapor into the other part up until a certain pressure has been attained in said outlet part. Once this predetermined pressure has been attained, the pressure responsive means closes the vapor inlet valve and opens the outlet valve for a time sufficient to lower the pressure in the part of the chamber corresponding to the vapor outlet, after which the pressure responsive device again opens the vapor inlet valve so that the cycle recommences.

When it is desired to create alternations according to the invention in the direction of passage of the vapor through the textile material, each of the two parts is provided with a supply duct and a outlet duct as well as a pressure responsive device.

In an advantageous application, the device according to the invention is provided with a duct permitting a vacuum to be established in the chamber. Moreover, heating devices and temperature control devices such as external coils may be provided.

Other advantages and characteristics of the invention will become apparent from a reading of the following description of one embodiment of the invention, given purely by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a schematic view showing a device of the autoclave type for carrying out the invention; and

FIG. 2 is a view of a container for holding textile material according to a variation of the invention.

The illustrated autoclave is vertically positioned and has a round bottom 2 forming the lower part through which vapor is exhausted and a cover 3 forming the upper part through which vapor is admitted. The textile material to be treated is positioned in a container 5 covered by a perforated plate 6, with a sealing member 7 between the container 5 and the perforated plate 6. Inside the autoclave is a ring 8 supporting through a second sealing member 9 the perforated bottom 10 of the container 5. It will thus be readily appreciated that the vapor admitted through the upper part above the container must necessarily pass through the material in the container in order to reach the lower part of the autoclave, because of the sealing member 9. An upper coil 11, provided with an inlet duct 11a and an outlet duct 11b, is welded to the cover 3, a drain being attached to this duct to evacuate condensed water.

In like manner, the curved bottom part is welded to a coil 12 the inlet duct 12a of which is connected to the inlet duct 11a and the exhaust 12b of which is also provided with a drain. Finally a last coil 13 provided with its own inlet duct 13a and its own exhaust 13b encircles the vertical part of the autoclave 1.. The inlet valve 130 of the coil 13 is controlled by a thermostat 14 for regulating the temperature around the autoclave. A duct 15 leads into the cover and has a first branch leading to an automatic vapor inlet valve 16 whereas its other branch leads to an automatic valve 17 through which the vapor may be evacuated. The arrows on the drawing show the directions in which the vapor circulates under the control of these valves.

In like manner the bottom 2 of the autoclave is provided with a duct 18, one branch of which leads to an automatic valve 19 for admitting vapor to the bottom of the autoclave, whereas another branch leads to an automatic valve 20 permitting the exhaust of the vapor from the bottom of the autoclave. Finally, another automatic valve 21 positioned in the duct 18 makes it possible to create a partial or high vacuum, as necessary, inside the autoclave.

A first pressure responsive means 22 is responsive to the pressure in the autoclave bottom part 2, that is to say beneath the container 5, and controls the valves 16 and 20, whereas a second pressure responsive means responsive to the pressure in the upper part of the chamber 5, which pressure is equal to the pressure at the level of the cover 3 controls the valves 17 and 19. The vapor outlet valves 17 and 20 may be connected to a vacuum pump or to any source of subatmospheric pressure, or even to atmospheric pressure, or to any other means for providing a relatively low pressure.

In a first method of carrying out the process according to the invention, after having placed the container 5 in the autoclave with the textile material 4 therein, vapor is introduced into the autoclave from the top, that is to say the vapor arrives through the valve 16, passes through the material and leaves through the valve 20. If the treatment pressure of the fibers is less than atmospheric pressure, a partial vacuum is first created to the extent required by regulating the valve 21. For such a vacuum treatment, the vapor outlet valves 17 and 20 (or one of them only, if the vapor travels in only one direction) are connected to a partial or high vacuum. Once a vacuum has been established in the autoclave, valve 21 is closed and the pressure responsive means 22 preset to the predetermined treatment pressure, opens the valve 16. The vapor is then admitted to the inside of the autoclave and as the vapor passes through the textile material the pressure increases little by little in the bottom 2 of the autoclave. When the pressure recorded on the pressure responsive means 22 is obtained, the valve 16 closes and the valve 20 opens which results in a rapid pressure drop. Under these conditions pressure responsive means 22 again opens the valve 16 and closes the valve 2% and the same cycle recommences. The time may be regulated from zero to several seconds between the closing of 22 and the opening of 16 to leave more time for the equalization of pressure.

If the treatment is carried out at a pressure greater than atmospheric, the operation is identical, but it is not necessary to first create a vacuum in the autoclave by opening the valve 21. It will be appreciated that, in accordance with the invention, in the initial phase of each alternation, the substantial difference between the pressure prevailing in the upper part of the autoclave at the level of the top 3 and in the lower part at the level of the bottom 2, causes the vapor to pass rapidly through the textile material. In the second stage of the alternation pressures are substantially equalized between the upper and lower parts of the autoclave and this insures a constant temperature in the textile material. This temperature is maintained practically constant during the initial alternating phase while the pressure decreases rapidly at the bottom of the autoclave, and the vapor again begins to pass through the textile material.

There is thus attained a treatment under conditions which appear difficult to simultaneously establish, that is to say good passage of the vapor through the textile material and a control of the temperature inside the textile material.

Of course it would be possible to speed up the final phase of each pressure-equalizing alternation by introducing vapor through the valve 19 which would rapidly bring the top and bottom of the autoclave to an identical pressure.

The autoclave described may also be used for a second method of carrying out the invention in which the vapor also circulates in the opposite direction from bottom to top within the autoclave. To this end, the pressure responsive means 23 is preset to the pressure desired in the upper part of the autoclave. This pressure responsive means 23 controls the opening of the lower vapor inlet valve 19 and, when the desired pressure is reached in the upper part of the autoclave, the valve 19 is closed by the pressure responsive means and the upper vapor exhaust valve 17 is opened. The pressure at the level of the pressure responsive means 23 then decreases rapidly, which results in closing the exhaust valve 17 and opening the lower inlet valve N. This cycle is repeated several times and may obviously be combined with cycles in the reverse direction controlled by the pressure responsive means 22. It is also possible to alternate the roles of the pressure responsive devices 22 and 23 which amounts to saying that regulation is carried out in response to the pressure upstream rather than downstream of the material 4 in the container 5. This pressure is attained more rapidly than the downstream pressure which results in shorter injection times, a characteristic which is advantageous in certain circumstances.

At the end of the treatment at least one of the valves 17 and is opened and the autoclave may be opened to extract the container holding the material.

The thermostat 14 insures the regulation of the temperature of the wall of the autoclave by controlling the valve 13a of the coil 13, but may also actuate the valve 110 to supply the upper coil 11 and the lower coil 12. Two particular examples of the process according to the invention will now be given. In the first example, the process according to the invention is applied to the shrinking of polyester cables at a temperature of 97.5 C, that is to say strips made of threads placed parallel to each other on a special machine utilizing a force to produce fissuring.

With the walls of the autoclave maintained at a temperature at least equal to 97.5 C by the coils 11, 12 and 13 controlled by the thermometer 14, the container 5 holding the polyester ribbon 4 is placed inside the autoclave.

The valves 17, 20 and 21. are first connected to a vacuum pump or an atmospheric or subatmospheric pressure, the valve 21 being opened for 30 seconds. This makes it possible to create an adequate vacuum in the autoclave. At the end of these 30 seconds the valve 20 is closed, and the valve 16 is opened to admit vapor. Once the pressure responsive means 22 has detected a pressure corresponding exactly to the temperature of 97.5 C, that is to say, an absolute pressure of 0.94 kg/cm the valve in closes and the valve 20 opens. Then, during the pressure drop, the valve 20 closes and the valve l6 opens. This succession of alternations takes place for a predetermined time of 1 minute. Once this minute has passed, the direction of operation is reversed for 1 minute, with the vapor now entering through the valve 19 and leaving through the valve 27 with alternations of equalization and pressure difference. After this second minute, the valves 16 and 19 are closed and the valves 17, 20 and 2f opened for 1 minute. After this minute, the valve 21 is closed and the valves 17 and 20 connected to atmosphere to eliminate the vacuum inside the autoclave and permit opening of the port 3. After opening, the container 5 is removed and it is found that the material has shrunk in a perfectly homogeneous manner.

It will be seen that the process and apparatus according to the invention make it possible to operate in an extremely rapid manner, because in 5 or 6 minutes it is possible to do the same work which, in the autoclaves presently in use, is accomplished in from an hour to an hour and one-half.

In a second example, tergal is vaporized at a temperature of ll7.5 C, which makes it unnecessary to connect the valves l7 and 2@ to vacuum. The process is otherwise the same as the one which has just been described.

In both of these examples it is possible to replace the polyester material by an acrylic strand without changing the method of operation. However, for very delicate fibers, it is necessary to obtain an even greater homogeneity of pressure by increasing by several seconds the time during which the valve for extracting vapor is closed and the valve for admitting vapor is not yet open.

Referring now to FIG. 2, in the variation illustrated in this figure, the textile material 4 is positioned inside a container 24, also located by means of a seal 9 on the seat 8. The container 24 may be open or closed at its upper end or provided with a grill such as 6. The lateral wall 25 of the container 24 is provided with a multitude of perforations connecting the space and the autoclave above the seal 9 and which lead to the upper part 3 and to almost the entire outer surface of the material 4, except for the lower surface of this material. Inside the material is a perforated tube 26 in direct communication with the lower part 2 of the chamber. In this man ner, when vapor is introduced through the lower part of the chamber, the vapor penetrates into the interior of the material and leaves the material by its external surface. On the contrary, when the vapor arrives through the upper part 3, the vapor penetrates through the upper surface of the material and leaves through the perforated tube 6. in a variation it is possible to extend the orifice 26 up to the upper surface of the material d by closing the top of the container, that is to say, by using a hennetic plate in place of the grill 6, and in this manner the vapor H circulates only radially between the perforated lateral wall 25 of the container 24 and the concentric perforated tube 26. In order to still further increase the time saved by the process according to the invention, it may be advantageous to make the supply and exhaust to the container automatic by positioning an autoclave at the outlet of each fissuring device, whereas with conventional autoclaves it is necessary to place a plurality of containers therein which produce different fissuring effects.

While the invention has been described in a particular form, it will be appreciated that it may be modified as to detail without thereby departing from the basic principles thereof.

What is claimed is:

1. Process for vapor treating textile materials in which vapor is passed through the textile material by establishing a pressure difference between the side of said material to which said vapor is supplied and the side from which it is exhausted and then momentarily preventing the passage of vapor through said material while substantially equalizing the pressures on each side thereof, and repeating these steps of establishing successive pressure difference and pressure equalizations.

2. Process as claimed in claim l during which the vapor passes through the material in opposite directions during different portions of the treating time.

3. Process as claimed in claim 1 in which the step of establishing a pressure difference includes the estab= lishment of at least a partial vacuum in a chamber containing the textile material.

4. Process as claimed in claim I in which a duct is inserted into the center of the material with vapor entering through said duct leaving through the external surface of the material, and vice versa. 

2. Process as claimed in claim 1 during which the vapor passes through the material in opposite directions during different portions of the treating time.
 3. Process as claimed in claim 1 in which the step of establishing a pressure difference includes the establishment of at least a partial vacuum in a chamber containing the textile material.
 4. Process as claimed in claim 1 in which a duct is inserted into the center of the material with vapor entering through said duct leaving through the external surface of the material, and vice versa. 